fdo#78903: Write test for this.

Change-Id: If8ed8b74b58efd948772376a14172b52ff588f82
fdo#78903: Don't broadcast prematurely during cell deletion.

We need to wait until all the affected cells get marked dirty at the
end of the deletion process.

Change-Id: I49618fcc386ec2209f5f0267d50257ecb8dd21d1